src/Pure/Isar/code.ML
changeset 24219 e558fe311376
child 24283 8ca96f4e49cd
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/Isar/code.ML	Fri Aug 10 17:04:34 2007 +0200
@@ -0,0 +1,925 @@
+(*  Title:      Pure/Isar/code.ML
+    ID:         $Id$
+    Author:     Florian Haftmann, TU Muenchen
+
+Abstract executable content of theory.  Management of data dependent on
+executable content.
+*)
+
+signature CODE =
+sig
+  val add_func: bool -> thm -> theory -> theory
+  val del_func: thm -> theory -> theory
+  val add_funcl: CodeUnit.const * thm list Susp.T -> theory -> theory
+  val add_func_attr: bool -> Attrib.src
+  val add_inline: thm -> theory -> theory
+  val del_inline: thm -> theory -> theory
+  val add_inline_proc: string * (theory -> cterm list -> thm list) -> theory -> theory
+  val del_inline_proc: string -> theory -> theory
+  val add_preproc: string * (theory -> thm list -> thm list) -> theory -> theory
+  val del_preproc: string -> theory -> theory
+  val add_post: thm -> theory -> theory
+  val del_post: thm -> theory -> theory
+  val add_datatype: string * ((string * sort) list * (string * typ list) list)
+    -> theory -> theory
+  val add_datatype_consts: CodeUnit.const list -> theory -> theory
+  val add_datatype_consts_cmd: string list -> theory -> theory
+
+  val coregular_algebra: theory -> Sorts.algebra
+  val operational_algebra: theory -> (sort -> sort) * Sorts.algebra
+  val these_funcs: theory -> CodeUnit.const -> thm list
+  val get_datatype: theory -> string -> ((string * sort) list * (string * typ list) list)
+  val get_datatype_of_constr: theory -> CodeUnit.const -> string option
+  val default_typ: theory -> CodeUnit.const -> typ
+
+  val preprocess_conv: cterm -> thm
+  val postprocess_conv: cterm -> thm
+
+  val add_attribute: string * (Args.T list -> attribute * Args.T list) -> theory -> theory
+
+  val print_codesetup: theory -> unit
+end;
+
+signature CODE_DATA_ARGS =
+sig
+  type T
+  val empty: T
+  val merge: Pretty.pp -> T * T -> T
+  val purge: theory option -> CodeUnit.const list option -> T -> T
+end;
+
+signature CODE_DATA =
+sig
+  type T
+  val get: theory -> T
+  val change: theory -> (T -> T) -> T
+  val change_yield: theory -> (T -> 'a * T) -> 'a * T
+end;
+
+signature PRIVATE_CODE =
+sig
+  include CODE
+  val declare_data: Object.T -> (Pretty.pp -> Object.T * Object.T -> Object.T)
+    -> (theory option -> CodeUnit.const list option -> Object.T -> Object.T) -> serial
+  val get_data: serial * ('a -> Object.T) * (Object.T -> 'a)
+    -> theory -> 'a
+  val change_data: serial * ('a -> Object.T) * (Object.T -> 'a)
+    -> theory -> ('a -> 'a) -> 'a
+  val change_yield_data: serial * ('a -> Object.T) * (Object.T -> 'a)
+    -> theory -> ('a -> 'b * 'a) -> 'b * 'a
+end;
+
+structure Code : PRIVATE_CODE =
+struct
+
+(** preliminaries **)
+
+structure Consttab = CodeUnit.Consttab;
+
+
+(* certificate theorems *)
+
+fun string_of_lthms r = case Susp.peek r
+ of SOME thms => (map string_of_thm o rev) thms
+  | NONE => ["[...]"];
+
+fun pretty_lthms ctxt r = case Susp.peek r
+ of SOME thms => map (ProofContext.pretty_thm ctxt) thms
+  | NONE => [Pretty.str "[...]"];
+
+fun certificate thy f r =
+  case Susp.peek r
+   of SOME thms => (Susp.value o f thy) thms
+     | NONE => let
+          val thy_ref = Theory.check_thy thy;
+        in Susp.delay (fn () => (f (Theory.deref thy_ref) o Susp.force) r) end;
+
+fun merge' _ ([], []) = (false, [])
+  | merge' _ ([], ys) = (true, ys)
+  | merge' eq (xs, ys) = fold_rev
+      (fn y => fn (t, xs) => (t orelse not (member eq xs y), insert eq y xs)) ys (false, xs);
+
+fun merge_alist eq_key eq (xys as (xs, ys)) =
+  if eq_list (eq_pair eq_key eq) (xs, ys)
+  then (false, xs)
+  else (true, AList.merge eq_key eq xys);
+
+val merge_thms = merge' Thm.eq_thm_prop;
+
+fun merge_lthms (r1, r2) =
+  if Susp.same (r1, r2)
+    then (false, r1)
+  else case Susp.peek r1
+   of SOME [] => (true, r2)
+    | _ => case Susp.peek r2
+       of SOME [] => (true, r1)
+        | _ => (apsnd (Susp.delay o K)) (merge_thms (Susp.force r1, Susp.force r2));
+
+
+(* pairs of (selected, deleted) defining equations *)
+
+type sdthms = thm list Susp.T * thm list;
+
+fun add_drop_redundant thm (sels, dels) =
+  let
+    val thy = Thm.theory_of_thm thm;
+    val args_of = snd o strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of;
+    val args = args_of thm;
+    fun matches [] _ = true
+      | matches (Var _ :: xs) [] = matches xs []
+      | matches (_ :: _) [] = false
+      | matches (x :: xs) (y :: ys) = Pattern.matches thy (x, y) andalso matches xs ys;
+    fun drop thm' = not (matches args (args_of thm'))
+      orelse (warning ("code generator: dropping redundant defining equation\n" ^ string_of_thm thm'); false);
+    val (keeps, drops) = List.partition drop sels;
+  in (thm :: keeps, dels |> remove Thm.eq_thm_prop thm |> fold (insert Thm.eq_thm_prop) drops) end;
+
+fun add_thm thm (sels, dels) =
+  apfst Susp.value (add_drop_redundant thm (Susp.force sels, dels));
+
+fun add_lthms lthms (sels, []) =
+      (Susp.delay (fn () => fold add_drop_redundant
+        (Susp.force lthms) (Susp.force sels, []) |> fst), [])
+        (*FIXME*)
+  | add_lthms lthms (sels, dels) =
+      fold add_thm (Susp.force lthms) (sels, dels);
+
+fun del_thm thm (sels, dels) =
+  (Susp.value (remove Thm.eq_thm_prop thm (Susp.force sels)), thm :: dels);
+
+fun pretty_sdthms ctxt (sels, _) = pretty_lthms ctxt sels;
+
+fun merge_sdthms ((sels1, dels1), (sels2, dels2)) =
+  let
+    val (dels_t, dels) = merge_thms (dels1, dels2);
+  in if dels_t
+    then let
+      val (_, sels) = merge_thms
+        (subtract Thm.eq_thm_prop dels2 (Susp.force sels1), Susp.force sels2);
+      val (_, dels) = merge_thms
+        (subtract Thm.eq_thm_prop (Susp.force sels2) dels1, dels2);
+    in (true, ((Susp.delay o K) sels, dels)) end
+    else let
+      val (sels_t, sels) = merge_lthms (sels1, sels2);
+    in (sels_t, (sels, dels)) end
+  end;
+
+
+(* code attributes *)
+
+structure CodeAttr = TheoryDataFun (
+  type T = (string * (Args.T list -> attribute * Args.T list)) list;
+  val empty = [];
+  val copy = I;
+  val extend = I;
+  fun merge _ = AList.merge (op =) (K true);
+);
+
+fun add_attribute (attr as (name, _)) =
+  let
+    fun add_parser ("", parser) attrs = attrs @ [("", parser)]
+      | add_parser (name, parser) attrs = (name, Args.$$$ name |-- parser) :: attrs;
+    fun error "" = error ("Code attribute already declared")
+      | error name = error ("Code attribute " ^ name ^ " already declared")
+  in CodeAttr.map (fn attrs => if AList.defined (op =) attrs name
+    then error name else add_parser attr attrs)
+  end;
+
+val _ =
+  let
+    val code_attr = Attrib.syntax (Scan.peek (fn context =>
+      List.foldr op || Scan.fail (map snd (CodeAttr.get (Context.theory_of context)))));
+  in
+    Context.add_setup (Attrib.add_attributes
+      [("code", code_attr, "declare theorems for code generation")])
+  end;
+
+
+
+(** exeuctable content **)
+
+datatype thmproc = Preproc of {
+  inlines: thm list,
+  inline_procs: (string * (serial * (theory -> cterm list -> thm list))) list,
+  preprocs: (string * (serial * (theory -> thm list -> thm list))) list,
+  posts: thm list
+};
+
+fun mk_thmproc (((inlines, inline_procs), preprocs), posts) =
+  Preproc { inlines = inlines, inline_procs = inline_procs, preprocs = preprocs,
+    posts = posts };
+fun map_thmproc f (Preproc { inlines, inline_procs, preprocs, posts }) =
+  mk_thmproc (f (((inlines, inline_procs), preprocs), posts));
+fun merge_thmproc (Preproc { inlines = inlines1, inline_procs = inline_procs1,
+    preprocs = preprocs1, posts = posts1 },
+  Preproc { inlines = inlines2, inline_procs = inline_procs2,
+      preprocs = preprocs2, posts= posts2 }) =
+    let
+      val (touched1, inlines) = merge_thms (inlines1, inlines2);
+      val (touched2, inline_procs) = merge_alist (op =) (eq_fst (op =)) (inline_procs1, inline_procs2);
+      val (touched3, preprocs) = merge_alist (op =) (eq_fst (op =)) (preprocs1, preprocs2);
+      val (_, posts) = merge_thms (posts1, posts2);
+    in (touched1 orelse touched2 orelse touched3,
+      mk_thmproc (((inlines, inline_procs), preprocs), posts)) end;
+
+fun join_func_thms (tabs as (tab1, tab2)) =
+  let
+    val cs1 = Consttab.keys tab1;
+    val cs2 = Consttab.keys tab2;
+    val cs' = filter (member CodeUnit.eq_const cs2) cs1;
+    val cs'' = subtract (op =) cs' cs1 @ subtract (op =) cs' cs2;
+    val cs''' = ref [] : CodeUnit.const list ref;
+    fun merge c x = let val (touched, thms') = merge_sdthms x in
+      (if touched then cs''' := cons c (!cs''') else (); thms') end;
+  in (cs'' @ !cs''', Consttab.join merge tabs) end;
+fun merge_funcs (thms1, thms2) =
+  let
+    val (consts, thms) = join_func_thms (thms1, thms2);
+  in (SOME consts, thms) end;
+
+val eq_string = op = : string * string -> bool;
+val eq_co = op = : (string * typ list) * (string * typ list) -> bool;
+fun eq_dtyp ((vs1, cs1), (vs2, cs2)) = 
+  gen_eq_set (eq_pair eq_string (gen_eq_set eq_string)) (vs1, vs2)
+    andalso gen_eq_set eq_co (cs1, cs2);
+fun merge_dtyps (tabs as (tab1, tab2)) =
+  let
+    val tycos1 = Symtab.keys tab1;
+    val tycos2 = Symtab.keys tab2;
+    val tycos' = filter (member eq_string tycos2) tycos1;
+    val new_types = not (gen_eq_set (op =) (tycos1, tycos2));
+    val diff_types = not (gen_eq_set (eq_pair (op =) eq_dtyp)
+      (AList.make (the o Symtab.lookup tab1) tycos',
+       AList.make (the o Symtab.lookup tab2) tycos'));
+    fun join _ (cos as (_, cos2)) = if eq_dtyp cos
+      then raise Symtab.SAME else cos2;
+  in ((new_types, diff_types), Symtab.join join tabs) end;
+
+datatype spec = Spec of {
+  funcs: sdthms Consttab.table,
+  dtyps: ((string * sort) list * (string * typ list) list) Symtab.table
+};
+
+fun mk_spec (funcs, dtyps) =
+  Spec { funcs = funcs, dtyps = dtyps };
+fun map_spec f (Spec { funcs = funcs, dtyps = dtyps }) =
+  mk_spec (f (funcs, dtyps));
+fun merge_spec (Spec { funcs = funcs1, dtyps = dtyps1 },
+  Spec { funcs = funcs2, dtyps = dtyps2 }) =
+  let
+    val (touched_cs, funcs) = merge_funcs (funcs1, funcs2);
+    val ((new_types, diff_types), dtyps) = merge_dtyps (dtyps1, dtyps2);
+    val touched = if new_types orelse diff_types then NONE else touched_cs;
+  in (touched, mk_spec (funcs, dtyps)) end;
+
+datatype exec = Exec of {
+  thmproc: thmproc,
+  spec: spec
+};
+
+fun mk_exec (thmproc, spec) =
+  Exec { thmproc = thmproc, spec = spec };
+fun map_exec f (Exec { thmproc = thmproc, spec = spec }) =
+  mk_exec (f (thmproc, spec));
+fun merge_exec (Exec { thmproc = thmproc1, spec = spec1 },
+  Exec { thmproc = thmproc2, spec = spec2 }) =
+  let
+    val (touched', thmproc) = merge_thmproc (thmproc1, thmproc2);
+    val (touched_cs, spec) = merge_spec (spec1, spec2);
+    val touched = if touched' then NONE else touched_cs;
+  in (touched, mk_exec (thmproc, spec)) end;
+val empty_exec = mk_exec (mk_thmproc ((([], []), []), []),
+  mk_spec (Consttab.empty, Symtab.empty));
+
+fun the_thmproc (Exec { thmproc = Preproc x, ...}) = x;
+fun the_spec (Exec { spec = Spec x, ...}) = x;
+val the_funcs = #funcs o the_spec;
+val the_dtyps = #dtyps o the_spec;
+val map_thmproc = map_exec o apfst o map_thmproc;
+val map_funcs = map_exec o apsnd o map_spec o apfst;
+val map_dtyps = map_exec o apsnd o map_spec o apsnd;
+
+
+(* data slots dependent on executable content *)
+
+(*private copy avoids potential conflict of table exceptions*)
+structure Datatab = TableFun(type key = int val ord = int_ord);
+
+local
+
+type kind = {
+  empty: Object.T,
+  merge: Pretty.pp -> Object.T * Object.T -> Object.T,
+  purge: theory option -> CodeUnit.const list option -> Object.T -> Object.T
+};
+
+val kinds = ref (Datatab.empty: kind Datatab.table);
+val kind_keys = ref ([]: serial list);
+
+fun invoke f k = case Datatab.lookup (! kinds) k
+ of SOME kind => f kind
+  | NONE => sys_error "Invalid code data identifier";
+
+in
+
+fun declare_data empty merge purge =
+  let
+    val k = serial ();
+    val kind = {empty = empty, merge = merge, purge = purge};
+    val _ = change kinds (Datatab.update (k, kind));
+    val _ = change kind_keys (cons k);
+  in k end;
+
+fun invoke_empty k = invoke (fn kind => #empty kind) k;
+
+fun invoke_merge_all pp = Datatab.join
+  (invoke (fn kind => #merge kind pp));
+
+fun invoke_purge_all thy_opt cs =
+  fold (fn k => Datatab.map_entry k
+    (invoke (fn kind => #purge kind thy_opt cs) k)) (! kind_keys);
+
+end; (*local*)
+
+
+(* theory store *)
+
+local
+
+type data = Object.T Datatab.table;
+
+structure CodeData = TheoryDataFun
+(
+  type T = exec * data ref;
+  val empty = (empty_exec, ref Datatab.empty : data ref);
+  fun copy (exec, data) = (exec, ref (! data));
+  val extend = copy;
+  fun merge pp ((exec1, data1), (exec2, data2)) =
+    let
+      val (touched, exec) = merge_exec (exec1, exec2);
+      val data1' = invoke_purge_all NONE touched (! data1);
+      val data2' = invoke_purge_all NONE touched (! data2);
+      val data = invoke_merge_all pp (data1', data2');
+    in (exec, ref data) end;
+);
+
+val _ = Context.add_setup CodeData.init;
+
+fun ch r f = let val x = f (! r) in (r := x; x) end;
+fun thy_data f thy = f ((snd o CodeData.get) thy);
+
+fun get_ensure_init kind data_ref =
+  case Datatab.lookup (! data_ref) kind
+   of SOME x => x
+    | NONE => let val y = invoke_empty kind
+        in (change data_ref (Datatab.update (kind, y)); y) end;
+
+in
+
+(* access to executable content *)
+
+val get_exec = fst o CodeData.get;
+
+fun map_exec_purge touched f thy =
+  CodeData.map (fn (exec, data) => 
+    (f exec, ref (invoke_purge_all (SOME thy) touched (! data)))) thy;
+
+
+(* access to data dependent on abstract executable content *)
+
+fun get_data (kind, _, dest) = thy_data (get_ensure_init kind #> dest);
+
+fun change_data (kind, mk, dest) =
+  let
+    fun chnge data_ref f =
+      let
+        val data = get_ensure_init kind data_ref;
+        val data' = f (dest data);
+      in (change data_ref (Datatab.update (kind, mk data')); data') end;
+  in thy_data chnge end;
+
+fun change_yield_data (kind, mk, dest) =
+  let
+    fun chnge data_ref f =
+      let
+        val data = get_ensure_init kind data_ref;
+        val (x, data') = f (dest data);
+      in (x, (change data_ref (Datatab.update (kind, mk data')); data')) end;
+  in thy_data chnge end;
+
+end; (*local*)
+
+
+(* print executable content *)
+
+fun print_codesetup thy =
+  let
+    val ctxt = ProofContext.init thy;
+    val exec = get_exec thy;
+    fun pretty_func (s, lthms) =
+      (Pretty.block o Pretty.fbreaks) (
+        Pretty.str s :: pretty_sdthms ctxt lthms
+      );
+    fun pretty_dtyp (s, []) =
+          Pretty.str s
+      | pretty_dtyp (s, cos) =
+          (Pretty.block o Pretty.breaks) (
+            Pretty.str s
+            :: Pretty.str "="
+            :: separate (Pretty.str "|") (map (fn (c, []) => Pretty.str c
+                 | (c, tys) =>
+                     (Pretty.block o Pretty.breaks)
+                        (Pretty.str c :: Pretty.str "of" :: map (Pretty.quote o Sign.pretty_typ thy) tys)) cos)
+          );
+    val inlines = (#inlines o the_thmproc) exec;
+    val inline_procs = (map fst o #inline_procs o the_thmproc) exec;
+    val preprocs = (map fst o #preprocs o the_thmproc) exec;
+    val funs = the_funcs exec
+      |> Consttab.dest
+      |> (map o apfst) (CodeUnit.string_of_const thy)
+      |> sort (string_ord o pairself fst);
+    val dtyps = the_dtyps exec
+      |> Symtab.dest
+      |> map (fn (dtco, (vs, cos)) => (Sign.string_of_typ thy (Type (dtco, map TFree vs)), cos))
+      |> sort (string_ord o pairself fst)
+  in
+    (Pretty.writeln o Pretty.chunks) [
+      Pretty.block (
+        Pretty.str "defining equations:"
+        :: Pretty.fbrk
+        :: (Pretty.fbreaks o map pretty_func) funs
+      ),
+      Pretty.block (
+        Pretty.str "inlining theorems:"
+        :: Pretty.fbrk
+        :: (Pretty.fbreaks o map (ProofContext.pretty_thm ctxt)) inlines
+      ),
+      Pretty.block (
+        Pretty.str "inlining procedures:"
+        :: Pretty.fbrk
+        :: (Pretty.fbreaks o map Pretty.str) inline_procs
+      ),
+      Pretty.block (
+        Pretty.str "preprocessors:"
+        :: Pretty.fbrk
+        :: (Pretty.fbreaks o map Pretty.str) preprocs
+      ),
+      Pretty.block (
+        Pretty.str "datatypes:"
+        :: Pretty.fbrk
+        :: (Pretty.fbreaks o map pretty_dtyp) dtyps
+      )
+    ]
+  end;
+
+
+
+(** theorem transformation and certification **)
+
+fun common_typ_funcs [] = []
+  | common_typ_funcs [thm] = [thm]
+  | common_typ_funcs (thms as thm :: _) =
+      let
+        val thy = Thm.theory_of_thm thm;
+        fun incr_thm thm max =
+          let
+            val thm' = incr_indexes max thm;
+            val max' = Thm.maxidx_of thm' + 1;
+          in (thm', max') end;
+        val (thms', maxidx) = fold_map incr_thm thms 0;
+        val ty1 :: tys = map (snd o CodeUnit.head_func) thms';
+        fun unify ty env = Sign.typ_unify thy (ty1, ty) env
+          handle Type.TUNIFY =>
+            error ("Type unificaton failed, while unifying defining equations\n"
+            ^ (cat_lines o map Display.string_of_thm) thms
+            ^ "\nwith types\n"
+            ^ (cat_lines o map (CodeUnit.string_of_typ thy)) (ty1 :: tys));
+        val (env, _) = fold unify tys (Vartab.empty, maxidx)
+        val instT = Vartab.fold (fn (x_i, (sort, ty)) =>
+          cons (Thm.ctyp_of thy (TVar (x_i, sort)), Thm.ctyp_of thy ty)) env [];
+      in map (Thm.instantiate (instT, [])) thms' end;
+
+fun certify_const thy const thms =
+  let
+    fun cert thm = if CodeUnit.eq_const (const, fst (CodeUnit.head_func thm))
+      then thm else error ("Wrong head of defining equation,\nexpected constant "
+        ^ CodeUnit.string_of_const thy const ^ "\n" ^ string_of_thm thm)
+  in map cert thms end;
+
+
+
+(** operational sort algebra and class discipline **)
+
+local
+
+fun aggr_neutr f y [] = y
+  | aggr_neutr f y (x::xs) = aggr_neutr f (f y x) xs;
+
+fun aggregate f [] = NONE
+  | aggregate f (x::xs) = SOME (aggr_neutr f x xs);
+
+fun inter_sorts thy =
+  let
+    val algebra = Sign.classes_of thy;
+    val inters = curry (Sorts.inter_sort algebra);
+  in aggregate (map2 inters) end;
+
+fun specific_constraints thy (class, tyco) =
+  let
+    val vs = Name.invents Name.context "" (Sign.arity_number thy tyco);
+    val clsops = (these o Option.map snd o try (AxClass.params_of_class thy)) class;
+    val funcs = clsops
+      |> map (fn (clsop, _) => (clsop, SOME tyco))
+      |> map (Consttab.lookup ((the_funcs o get_exec) thy))
+      |> (map o Option.map) (Susp.force o fst)
+      |> maps these
+      |> map (Thm.transfer thy);
+    val sorts = map (map (snd o dest_TVar) o snd o dest_Type o the_single
+      o Sign.const_typargs thy o (fn ((c, _), ty) => (c, ty)) o CodeUnit.head_func) funcs;
+  in sorts end;
+
+fun weakest_constraints thy (class, tyco) =
+  let
+    val all_superclasses = class :: Graph.all_succs ((#classes o Sorts.rep_algebra o Sign.classes_of) thy) [class];
+  in case inter_sorts thy (maps (fn class => specific_constraints thy (class, tyco)) all_superclasses)
+   of SOME sorts => sorts
+    | NONE => Sign.arity_sorts thy tyco [class]
+  end;
+
+fun strongest_constraints thy (class, tyco) =
+  let
+    val algebra = Sign.classes_of thy;
+    val all_subclasses = class :: Graph.all_preds ((#classes o Sorts.rep_algebra) algebra) [class];
+    val inst_subclasses = filter (can (Sorts.mg_domain algebra tyco) o single) all_subclasses;
+  in case inter_sorts thy (maps (fn class => specific_constraints thy (class, tyco)) inst_subclasses)
+   of SOME sorts => sorts
+    | NONE => replicate
+        (Sign.arity_number thy tyco) (Sign.certify_sort thy (Sign.all_classes thy))
+  end;
+
+fun gen_classop_typ constr thy class (c, tyco) = 
+  let
+    val (var, cs) = try (AxClass.params_of_class thy) class |> the_default ("'a", [])
+    val ty = (the o AList.lookup (op =) cs) c;
+    val sort_args = Name.names (Name.declare var Name.context) "'a"
+      (constr thy (class, tyco));
+    val ty_inst = Type (tyco, map TFree sort_args);
+  in Logic.varifyT (map_type_tfree (K ty_inst) ty) end;
+
+fun retrieve_algebra thy operational =
+  Sorts.subalgebra (Sign.pp thy) operational
+    (weakest_constraints thy)
+    (Sign.classes_of thy);
+
+in
+
+fun coregular_algebra thy = retrieve_algebra thy (K true) |> snd;
+fun operational_algebra thy =
+  let
+    fun add_iff_operational class =
+      can (AxClass.get_definition thy) class ? cons class;
+    val operational_classes = fold add_iff_operational (Sign.all_classes thy) []
+  in retrieve_algebra thy (member (op =) operational_classes) end;
+
+val classop_weakest_typ = gen_classop_typ weakest_constraints;
+val classop_strongest_typ = gen_classop_typ strongest_constraints;
+
+fun assert_func_typ thm =
+  let
+    val thy = Thm.theory_of_thm thm;
+    fun check_typ_classop class (const as (c, SOME tyco), thm) =
+          let
+            val (_, ty) = CodeUnit.head_func thm;
+            val ty_decl = classop_weakest_typ thy class (c, tyco);
+            val ty_strongest = classop_strongest_typ thy class (c, tyco);
+            fun constrain thm = 
+              let
+                val max = Thm.maxidx_of thm + 1;
+                val ty_decl' = Logic.incr_tvar max ty_decl;
+                val (_, ty') = CodeUnit.head_func thm;
+                val (env, _) = Sign.typ_unify thy (ty_decl', ty') (Vartab.empty, max);
+                val instT = Vartab.fold (fn (x_i, (sort, ty)) =>
+                  cons (Thm.ctyp_of thy (TVar (x_i, sort)), Thm.ctyp_of thy ty)) env [];
+              in Thm.instantiate (instT, []) thm end;
+          in if Sign.typ_instance thy (ty_strongest, ty)
+            then if Sign.typ_instance thy (ty, ty_decl)
+            then thm
+            else (warning ("Constraining type\n" ^ CodeUnit.string_of_typ thy ty
+              ^ "\nof defining equation\n"
+              ^ string_of_thm thm
+              ^ "\nto permitted most general type\n"
+              ^ CodeUnit.string_of_typ thy ty_decl);
+              constrain thm)
+            else CodeUnit.bad_thm ("Type\n" ^ CodeUnit.string_of_typ thy ty
+              ^ "\nof defining equation\n"
+              ^ string_of_thm thm
+              ^ "\nis incompatible with permitted least general type\n"
+              ^ CodeUnit.string_of_typ thy ty_strongest)
+          end
+      | check_typ_classop class ((c, NONE), thm) =
+          CodeUnit.bad_thm ("Illegal type for class operation " ^ quote c
+           ^ "\nin defining equation\n"
+           ^ string_of_thm thm);
+    fun check_typ_fun (const as (c, _), thm) =
+      let
+        val (_, ty) = CodeUnit.head_func thm;
+        val ty_decl = Sign.the_const_type thy c;
+      in if Sign.typ_equiv thy (Type.strip_sorts ty_decl, Type.strip_sorts ty)
+        then thm
+        else CodeUnit.bad_thm ("Type\n" ^ CodeUnit.string_of_typ thy ty
+           ^ "\nof defining equation\n"
+           ^ string_of_thm thm
+           ^ "\nis incompatible with declared function type\n"
+           ^ CodeUnit.string_of_typ thy ty_decl)
+      end;
+    fun check_typ (const as (c, _), thm) =
+      case AxClass.class_of_param thy c
+       of SOME class => check_typ_classop class (const, thm)
+        | NONE => check_typ_fun (const, thm);
+  in check_typ (fst (CodeUnit.head_func thm), thm) end;
+
+val mk_func = CodeUnit.error_thm
+  (assert_func_typ o CodeUnit.mk_func);
+val mk_func_liberal = CodeUnit.warning_thm
+  (assert_func_typ o CodeUnit.mk_func);
+
+end;
+
+
+
+(** interfaces and attributes **)
+
+fun add_func true thm thy =
+      let
+        val func = mk_func thm;
+        val (const, _) = CodeUnit.head_func func;
+      in map_exec_purge (SOME [const]) (map_funcs
+        (Consttab.map_default
+          (const, (Susp.value [], [])) (add_thm func))) thy
+      end
+  | add_func false thm thy =
+      case mk_func_liberal thm
+       of SOME func => let
+              val (const, _) = CodeUnit.head_func func
+            in map_exec_purge (SOME [const]) (map_funcs
+              (Consttab.map_default
+                (const, (Susp.value [], [])) (add_thm func))) thy
+            end
+        | NONE => thy;
+
+fun delete_force msg key xs =
+  if AList.defined (op =) xs key then AList.delete (op =) key xs
+  else error ("No such " ^ msg ^ ": " ^ quote key);
+
+fun del_func thm thy =
+  let
+    val func = mk_func thm;
+    val (const, _) = CodeUnit.head_func func;
+  in map_exec_purge (SOME [const]) (map_funcs
+    (Consttab.map_entry
+      const (del_thm func))) thy
+  end;
+
+fun add_funcl (const, lthms) thy =
+  let
+    val lthms' = certificate thy (fn thy => certify_const thy const) lthms;
+      (*FIXME must check compatibility with sort algebra;
+        alas, naive checking results in non-termination!*)
+  in
+    map_exec_purge (SOME [const]) (map_funcs (Consttab.map_default (const, (Susp.value [], []))
+      (add_lthms lthms'))) thy
+  end;
+
+fun add_func_attr strict = Attrib.internal (fn _ => Thm.declaration_attribute
+  (fn thm => Context.mapping (add_func strict thm) I));
+
+local
+
+fun del_datatype tyco thy =
+  case Symtab.lookup ((the_dtyps o get_exec) thy) tyco
+   of SOME (vs, cos) => let
+        val consts = CodeUnit.consts_of_cos thy tyco vs cos;
+      in map_exec_purge (if null consts then NONE else SOME consts)
+        (map_dtyps (Symtab.delete tyco)) thy end
+    | NONE => thy;
+
+in
+
+fun add_datatype (tyco, (vs_cos as (vs, cos))) thy =
+  let
+    val consts = CodeUnit.consts_of_cos thy tyco vs cos;
+  in
+    thy
+    |> del_datatype tyco
+    |> map_exec_purge (SOME consts) (map_dtyps (Symtab.update_new (tyco, vs_cos)))
+  end;
+
+fun add_datatype_consts consts thy =
+  add_datatype (CodeUnit.cos_of_consts thy consts) thy;
+
+fun add_datatype_consts_cmd raw_cs thy =
+  add_datatype_consts (map (CodeUnit.read_const thy) raw_cs) thy
+
+end; (*local*)
+
+fun add_inline thm thy =
+  (map_exec_purge NONE o map_thmproc o apfst o apfst o apfst)
+    (insert Thm.eq_thm_prop (CodeUnit.error_thm CodeUnit.mk_rew thm)) thy;
+        (*fully applied in order to get right context for mk_rew!*)
+
+fun del_inline thm thy =
+  (map_exec_purge NONE o map_thmproc o apfst o apfst o apfst)
+    (remove Thm.eq_thm_prop (CodeUnit.error_thm CodeUnit.mk_rew thm)) thy;
+        (*fully applied in order to get right context for mk_rew!*)
+
+fun add_inline_proc (name, f) =
+  (map_exec_purge NONE o map_thmproc o apfst o apfst o apsnd)
+    (AList.update (op =) (name, (serial (), f)));
+
+fun del_inline_proc name =
+  (map_exec_purge NONE o map_thmproc o apfst o apfst o apsnd)
+    (delete_force "inline procedure" name);
+
+fun add_preproc (name, f) =
+  (map_exec_purge NONE o map_thmproc o apfst o apsnd)
+    (AList.update (op =) (name, (serial (), f)));
+
+fun del_preproc name =
+  (map_exec_purge NONE o map_thmproc o apfst o apsnd)
+    (delete_force "preprocessor" name);
+
+fun add_post thm thy =
+  (map_exec_purge NONE o map_thmproc o apsnd)
+    (insert Thm.eq_thm_prop (CodeUnit.error_thm CodeUnit.mk_rew thm)) thy;
+        (*fully applied in order to get right context for mk_rew!*)
+
+fun del_post thm thy =
+  (map_exec_purge NONE o map_thmproc o apsnd)
+    (remove Thm.eq_thm_prop (CodeUnit.error_thm CodeUnit.mk_rew thm)) thy;
+        (*fully applied in order to get right context for mk_rew!*)
+
+val _ = Context.add_setup
+  (let
+    fun mk_attribute f = Thm.declaration_attribute (fn thm => Context.mapping (f thm) I);
+    fun add_simple_attribute (name, f) =
+      add_attribute (name, Scan.succeed (mk_attribute f));
+    fun add_del_attribute (name, (add, del)) =
+      add_attribute (name, Args.del |-- Scan.succeed (mk_attribute del)
+        || Scan.succeed (mk_attribute add))
+  in
+    add_del_attribute ("func", (add_func true, del_func))
+    #> add_del_attribute ("inline", (add_inline, del_inline))
+    #> add_del_attribute ("post", (add_post, del_post))
+  end);
+
+
+(** post- and preprocessing **)
+
+local
+
+fun gen_apply_inline_proc prep post thy f x =
+  let
+    val cts = prep x;
+    val rews = map CodeUnit.assert_rew (f thy cts);
+  in post rews x end;
+
+val apply_inline_proc = gen_apply_inline_proc (maps
+  ((fn [args, rhs] => rhs :: (snd o Drule.strip_comb) args) o snd o Drule.strip_comb o Thm.cprop_of))
+  (fn rews => map (CodeUnit.rewrite_func rews));
+val apply_inline_proc_cterm = gen_apply_inline_proc single
+  (MetaSimplifier.rewrite false);
+
+fun apply_preproc thy f [] = []
+  | apply_preproc thy f (thms as (thm :: _)) =
+      let
+        val (const, _) = CodeUnit.head_func thm;
+        val thms' = f thy thms;
+      in certify_const thy const thms' end;
+
+fun rhs_conv conv thm =
+  let
+    val thm' = (conv o Thm.rhs_of) thm;
+  in Thm.transitive thm thm' end
+
+in
+
+fun preprocess thy thms =
+  thms
+  |> fold (fn (_, (_, f)) => apply_preproc thy f) ((#preprocs o the_thmproc o get_exec) thy)
+  |> map (CodeUnit.rewrite_func ((#inlines o the_thmproc o get_exec) thy))
+  |> fold (fn (_, (_, f)) => apply_inline_proc thy f) ((#inline_procs o the_thmproc o get_exec) thy)
+(*FIXME - must check: rewrite rule, defining equation, proper constant |> map (snd o check_func false thy) *)
+  |> common_typ_funcs;
+
+fun preprocess_conv ct =
+  let
+    val thy = Thm.theory_of_cterm ct;
+  in
+    ct
+    |> MetaSimplifier.rewrite false ((#inlines o the_thmproc o get_exec) thy)
+    |> fold (fn (_, (_, f)) => rhs_conv (apply_inline_proc_cterm thy f))
+        ((#inline_procs o the_thmproc o get_exec) thy)
+  end;
+
+fun postprocess_conv ct =
+  let
+    val thy = Thm.theory_of_cterm ct;
+  in
+    ct
+    |> MetaSimplifier.rewrite false ((#posts o the_thmproc o get_exec) thy)
+  end;
+
+end; (*local*)
+
+fun get_datatype thy tyco =
+  case Symtab.lookup ((the_dtyps o get_exec) thy) tyco
+   of SOME spec => spec
+    | NONE => Sign.arity_number thy tyco
+        |> Name.invents Name.context "'a"
+        |> map (rpair [])
+        |> rpair [];
+
+fun get_datatype_of_constr thy const =
+  case CodeUnit.co_of_const' thy const
+   of SOME (tyco, (_, co)) => if member eq_co
+        (Symtab.lookup (((the_dtyps o get_exec) thy)) tyco
+          |> Option.map snd
+          |> the_default []) co then SOME tyco else NONE
+    | NONE => NONE;
+
+fun get_constr_typ thy const =
+  case get_datatype_of_constr thy const
+   of SOME tyco => let
+        val (vs, cos) = get_datatype thy tyco;
+        val (_, (_, (co, tys))) = CodeUnit.co_of_const thy const
+      in (tys ---> Type (tyco, map TFree vs))
+        |> map_atyps (fn TFree (v, _) => TFree (v, AList.lookup (op =) vs v |> the))
+        |> Logic.varifyT
+        |> SOME end
+    | NONE => NONE;
+
+fun default_typ_proto thy (const as (c, SOME tyco)) = classop_weakest_typ thy
+      ((the o AxClass.class_of_param thy) c) (c, tyco) |> SOME
+  | default_typ_proto thy (const as (c, NONE)) = case AxClass.class_of_param thy c
+       of SOME class => SOME (Term.map_type_tvar
+            (K (TVar (("'a", 0), [class]))) (Sign.the_const_type thy c))
+        | NONE => get_constr_typ thy const;
+
+local
+
+fun get_funcs thy const =
+  Consttab.lookup ((the_funcs o get_exec) thy) const
+  |> Option.map (Susp.force o fst)
+  |> these
+  |> map (Thm.transfer thy);
+
+in
+
+fun these_funcs thy const =
+  let
+    fun drop_refl thy = filter_out (is_equal o Term.fast_term_ord o Logic.dest_equals
+      o ObjectLogic.drop_judgment thy o Thm.plain_prop_of);
+  in
+    get_funcs thy const
+    |> preprocess thy
+    |> drop_refl thy
+  end;
+
+fun default_typ thy (const as (c, _)) = case default_typ_proto thy const
+ of SOME ty => ty
+  | NONE => (case get_funcs thy const
+     of thm :: _ => snd (CodeUnit.head_func thm)
+      | [] => Sign.the_const_type thy c);
+
+end; (*local*)
+
+end; (*struct*)
+
+
+(** type-safe interfaces for data depedent on executable content **)
+
+functor CodeDataFun(Data: CODE_DATA_ARGS): CODE_DATA =
+struct
+
+type T = Data.T;
+exception Data of T;
+fun dest (Data x) = x
+
+val kind = Code.declare_data (Data Data.empty)
+  (fn pp => fn (Data x1, Data x2) => Data (Data.merge pp (x1, x2)))
+  (fn thy_opt => fn cs => fn Data x => Data (Data.purge thy_opt cs x));
+
+val data_op = (kind, Data, dest);
+
+val get = Code.get_data data_op;
+val change = Code.change_data data_op;
+fun change_yield thy = Code.change_yield_data data_op thy;
+
+end;
+
+structure Code : CODE =
+struct
+
+open Code;
+
+end;